Weak shells and in egg eating hens. What may start egg eating is the shells get weak due to low calcium, when a hen steps on the weak shell it breaks. Then to keep the nest clean the hen eats the egg. If it keeps happening the hen eventually gets to the liking of the eggs ending up with the nasty habit of egg eating. This is something that I think may sometimes start the egg eating problem. I don't think that that my theory has been proven.
Shiloh is my #1 egg eater. Isa Bro EE mix, mostly white with splashes of blue, very pretty hen. She likes to eat eggs for breakfast and now she hits her half sisters doing the same. When I give her lots of oyster shells mixed in the grain ( not separate ) she seems to slow down on the egg eating.
Oyster shell may help with your hens. I've heard of some people removing the membrane out off the shells, crushing them up, then feeding them back to their hens. I see it as the hens are still egg eating, but it may work.
Good luck with your Orps, I have one that is broody that I'm hoping to get her set up in some coop so she can hatch some chicks. If she hatched anything, it will be her 4th hatch. Her name is Joy.